Field of the Invention
The present invention relates to a conveying hand that holds a conveyed object, and relates to a lithography apparatus using the same.
Description of the Related Art
Conventionally, a conveying device in which a substrate, for example, a wafer for manufacturing semiconductor devices or a glass plate for manufacturing liquid crystal display devices serving as an conveyed object, has commonly conveyed the conveyed object while adsorbing and holding it by using a conveying hand having an adsorption pad. However, if warpage or distortion has occurred in the conveyed object, the surface of the conveyed object does not fit the adsorption surface of the adsorption pad, and as a result, efficient adsorption is impossible. Japanese Utility Model Registration Laid-Open No. H6-72974 discloses a conveying device in which an elastic member is disposed in the lower portion of the adsorption pad and the adsorption surface is accordingly made to fit the shape of the conveyed object even when warpage or distortion has occurred in the conveyed object. Additionally, Japanese Patent Laid-Open H8-229866 discloses an adsorption pad in which a coil spring is disposed in the lower portion of an adsorption member having an adsorption surface and the adsorption surface is accordingly made to fit the shape of the conveyed object.
However, in the techniques disclosed in the Japanese Utility Model Laid-Open No. H6-72974 and the Japanese Patent Laid-Open No. H8-229866, while the adsorption pad has a structure that flexibly absorbs the shape change of the conveyed object in the direction of gravity, it has a structure that causes a backlash in the plane direction perpendicular to the direction of gravity. Accordingly, there is a probability that the conveyed object shifts from the adsorption surface in the plane direction during the delivery or the conveyance of the object, thereby lowering the positioning accuracy during the conveyance.